Sedimentary rock is a type of rock formed from the accumulation and compression of mineral and organic particles over time. These particles can include fragments of other rocks, minerals, and even fossils. Sedimentary rocks often form in layers, which can be seen in cliffs and canyons, and they typically develop in environments like rivers, lakes, and oceans. There are three main types of sedimentary rock: clastic, which is made from broken pieces of other rocks; chemical, which forms from dissolved minerals that precipitate out of water; and biological, which is created from the remains of living organisms. These rocks are important for understanding Earth's history and are often rich in natural resources.